Laszlo,
> -----Original Message----- > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Laszlo Ersek > Sent: Thursday, November 14, 2019 7:08 PM > To: Wang, Jian J <jian.j.w...@intel.com>; Ard Biesheuvel > <ard.biesheu...@linaro.org> > Cc: devel@edk2.groups.io; Justen, Jordan L <jordan.l.jus...@intel.com>; Gao, > Liming <liming....@intel.com>; Ni, Ray <ray...@intel.com> > Subject: Re: [edk2-devel] [PATCH 08/11] OvmfPkg: specify RngLib instances in > dsc files > > Jian, Ard, > > commenting for both OvmfPkg and ArmVirtPkg: > > On 11/14/19 03:17, Wang, Jian J wrote: > > Per BZ1871, OpensslLib will depend on RngLib instead of TimerLib. > > Update OVMF dsc files to accommodate the coming changes. It's supposed > > that only TlsDxe needs random number. The DxeRngLibRngProtocol is added > > for it. For all other drivers, BaseRngLibNull is used by default. > > > > Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1871 > > Cc: Jordan Justen <jordan.l.jus...@intel.com> > > Cc: Laszlo Ersek <ler...@redhat.com> > > Cc: Ard Biesheuvel <ard.biesheu...@linaro.org> > > Cc: Liming Gao <liming....@intel.com> > > Cc: Ray Ni <ray...@intel.com> > > Signed-off-by: Jian J Wang <jian.j.w...@intel.com> > > --- > > OvmfPkg/OvmfPkgIa32.dsc | 5 +++++ > > OvmfPkg/OvmfPkgIa32X64.dsc | 5 +++++ > > OvmfPkg/OvmfPkgX64.dsc | 5 +++++ > > OvmfPkg/OvmfXen.dsc | 5 +++++ > > 4 files changed, 20 insertions(+) > > > > diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc > > index d350b75630..5a709a95b2 100644 > > --- a/OvmfPkg/OvmfPkgIa32.dsc > > +++ b/OvmfPkg/OvmfPkgIa32.dsc > > @@ -217,6 +217,7 @@ > > > > [LibraryClasses.common] > > BaseCryptLib|CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf > > + RngLib|MdePkg/Library/BaseRngLibNull/BaseRngLibNull.inf > > > > [LibraryClasses.common.SEC] > > TimerLib|OvmfPkg/Library/AcpiTimerLib/BaseRomAcpiTimerLib.inf > > @@ -786,6 +787,10 @@ > > <LibraryClasses> > > NULL|OvmfPkg/Library/TlsAuthConfigLib/TlsAuthConfigLib.inf > > } > > + NetworkPkg/TlsDxe/TlsDxe.inf { > > + <LibraryClasses> > > + > RngLib|SecurityPkg/RandomNumberGenerator/DxeRngLibRngProtocol/DxeRng > LibRngProtocol.inf > > + } > > !endif > > OvmfPkg/VirtioNetDxe/VirtioNet.inf > > > > This is not right for either OvmfPkg or ArmVirtPkg, because: > > - the virtual hardware is dynamic and might change from boot to boot, > > - EFI_RNG_PROTOCOL, implemented by VirtioRngDxe, only supports > EFI_RNG_ALGORITHM_RAW. > > I propose the following approach. > > (1) Jian, please do introduce all of the RngLib instances that you are > introducing in this v1 series, namely: > > - the null lib instance, > - the RDSEED lib instance, > - the DXE / protocol lib instance that directly requires NIST/ANSI > conformant algorithm support from the RNG protocol. > I agree. > (2) Jian, please add a *further* lib instance: a time based one. This > instance should basically extract the current functionality from > "rand_pool_noise.c" and "rand_pool_noise_tsc.c". (The code that you are > removing in patch #10.) > > It's also fine with me if, rather than factoring out the > rand_pool_noise*.c logic, you add a new "CPU jitter" based RngLib > instance. (Ard might disagree with me about this alternative -- the > point is that we should have a library instance that provides *some* > (even if barely tolerable) randomness, but with no dependency on > *optional* hardware. In other words, this lib instance should depend on > *guaranteed* platform hardware only. TSC, TimerLib, etc.) > Either is fine with me. I'll let you and Ard to make decision. > (3) For OvmfPkg and ArmVirtPkg, please write patches that: > > - provide a default resolution to the Null instance, > > - resolve RngLib to the time-based instance, for TlsDxe *only*. > Ok. I'll update those dsc in v2. > At that point, we will have made ArmVirtPkg and OvmfPkg *independent* of > the rest of this series -- ArmVirtPkg and OvmfPkg will not block this > patch series, they will also not suffer any regressions, and we can go > ahead and implement a separate RngLib instance for TlsDxe ourselves. > > > Now, let me lay out my proposal for *that* RngLib instance. (I'm willing > to write it a good chunk of it, but I will need help from Ard minimally > in the crypto code.) > > - The CONSTRUCTOR function should register an End-of-Dxe notification > function. In that function, (a) a boolean flag (such as "mEndOfDxe") > should be flipped from FALSE to TRUE, and (b) a pointer to > EFI_RNG_PROTOCOL should be saved (if such a protocol exists), such as > "mRngProtocol". > > - each RngLib API in this lib instance should hang, if "mEndOfDxe" is > FALSE at the time of the call (--> CpuDeadLoop() etc) > > - otherwise, if "mRngProtocol" is not NULL, it should be used to fetch > *raw* entropy. That raw entropy should be mixed sufficiently for NIST / > ANSI conformance. (I hope this statement makes sense.) This is where I'd > absolutely need help from Ard. > > - otherwise, on IA32/X64 only, if CPUID indicates that RDSEED is > supported by the processor, call RDSEED. > > - otherwise, on IA32/X64 only, if CPUID indicates that RDRAND is > supported by the processor, call RDRAND. > > - otherwise, on all arches, scrape some timer-based entropy, "from the > bottom of the barrel" (possibly in an arch-specific way, e.g. we could > use TSC on IA32/X64). > > - The platform BDS code for OVMF and ArmVirtQemu* should bind the > virtio-rng device to VirtioRngDxe *before* signaling End-of-Dxe. > > > The basic idea is that this RngLib instance should give the platform a > *chance* to produce an EFI_RNG_PROTOCOL instance until End-of-Dxe. If > that happens, then continue consuming raw entropy from *that* source, > and mix it manually for NIST / ANSI conformance. Otherwise, gracefully > degrade to the next strongest entropy source that's dynamically detected > on the platform (RDSEED or RDRAND, per CPUID -- on IA32/X64 only --, and > then timer-based -- on all platforms). > I'm curious that you want to do the "degrade" dynamically at boot time not build time, right? Thanks, Jian > Thanks > Laszlo > > > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#50670): https://edk2.groups.io/g/devel/message/50670 Mute This Topic: https://groups.io/mt/56714143/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
